Copy-protection of software applications is one of the important concerns of any software vendor. In order to prevent unauthorized copying, or at least make it more difficult, many systems look at certain attributes, such as a host identification key (“host ID”) and compare it to a license file. If the host ID is authorized, the software executes. If the Host ID doesn't match, the operator of the system needs to acquire an appropriate license corresponding to the system in order for the software to work.
Prevention of unauthorized copying becomes more problematic in virtual environments where the host ID changes but not due to an event that would terminate the authorization granted by the license. Utilization of a media access control (“MAC”) address is useful, provided one has access to the physical device hosting the software. Virtual machine (“VM”) pose a problem to MAC address authentication since they do not have access to the physical machine or, if access is provided, it is not consistent as the underlying hardware may change.
As a result, a data center running an application on a virtual machine may be authorized to use a particular software application. An upgrade to the VM may cause the host ID to change. Once changed, any licenses that are verified against a previous host ID will cause the associated software or features to be unable to verify the license with the upgraded host ID and may cause the software to stop operating. Similarly, redundant license servers may host a single license file containing the host IDs for all the systems supported. The file must be maintained with current host IDs and licenses referencing the current host IDs. When a host ID changes, the administrative burden can be substantial. After an upgrade, the operator of the VM or licensing server supporting a VM, must contact the vendor and obtain a new license file. Until the updated license file is obtained, the software may be inoperable.